Making an Impression

A boulloterion, like this, was an iron tool similar to a large set of iron pliers. The jaws were carved with the negative of the image and inscription to be pressed into the blank. To create a seal, the blank was clamped in the jaws of the boulloterion. The top was then struck with a hammer, which collapsed the channel, secured the cord, and imprinted the design onto the blank. 

Only a handful of boulloteria survive; the rest were melted down either for security reasons or for their iron. This example depicts St. Nicholas on one jaw and an inscription naming its owner as Stephen on the other.

Image Source

• Boulloterion of Stephen, proedros (eleventh century). 1951.31.6, Harvard Art Museums/Arthur M. Sackler Museum, Bequest of Thomas Whittemore